Electrical wire with terminals

Abstract

To provide an electric wire with a terminal, which can suppress the increase of a resistance ratio.SOLUTION: The electric wire with the terminal comprises: a center conductor; conductor layers provided two or more on the outer circumference side and having a plurality of conductors arrayed in a circumferential direction; an insulator layer that covers the conductor layers; and the terminal caulked and fitted to the ends of the conductors. The two or more conductor layers include an aluminum layer and a copper layer disposed closer to the outer circumference side than the aluminum layer. A value of X in the following expression (1) is 0 / °C to 3.4×10-6 / °C. Expression (1) X=(d0×K0+2×Σ(di×Ki)-D×KT) / D. In the expression (1), D denotes a diameter of a part composed of the center conductor and the two or more conductor layers, KT denotes a linear expansion coefficient of a material of the terminal, d0 denotes a diameter of the center conductor, K0 denotes a linear expansion coefficient of the center conductor, di denotes a diameter of a conductor included in the two or more conductor layers, Ki denotes a linear expansion coefficient of the conductor of the diameter di, and Σ(di×Ki) denotes a total value of (di×Ki) calculated at each of the two or more conductor layers.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an electric wire with a terminal.

Background Art

[0002] Patent Document 1 discloses an electric wire. The electric wire includes a conductor and an insulator layer. The insulator layer covers the conductor. By attaching a terminal to the end of the electric wire, an electric wire with a terminal is manufactured. As the terminal, a copper terminal is used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When an electric wire with a terminal is placed in an environment with a large temperature change, the resistance ratio tends to increase. In one aspect of the present disclosure, it is preferable to provide an electric wire with a terminal that can suppress the increase in the resistance ratio.

Means for Solving the Problems

[0005] One aspect of the present disclosure is an electric wire with a terminal, comprising a central conductor, a conductor layer provided with two or more layers on the outer peripheral side of the central conductor and formed by a plurality of conductors arranged side by side in the circumferential direction, an insulator layer covering the conductor layer, and a terminal caulked and attached to the end of the conductor. The two or more conductor layers include an aluminum layer formed by arranging conductors containing aluminum side by side in the circumferential direction, and a copper layer formed by arranging conductors containing copper side by side in the circumferential direction and disposed on the outer peripheral side of the aluminum layer.

[0006] The value of X defined by the following formula (1) is 0 / °C or more and 3.4×10 -6 / °C or less. Formula (1) X=(d0×K0 + 2×Σ(di ×K i ) - D×K T ) / D (In Formula (1), D is the diameter before caulking of the portion composed of the central conductor and the two or more conductor layers. K T is the linear expansion coefficient of the material of the terminal. d0 is the diameter before caulking of the central conductor. K0 is the linear expansion coefficient of the central conductor. d i is the diameter before caulking of the conductor included in the two or more conductor layers. K i is the diameter of the conductor with diameter d i [[ID=……]] is the linear expansion coefficient of the conductor with diameter d i ×K i ) is the total value of (d i ×K i ) calculated for each of the two or more conductor layers.) The electric wire with a terminal, which is one aspect of the present disclosure, is unlikely to have an increased resistance ratio even in an environment with drastic temperature changes.

Brief Description of the Drawings

[0007] [Figure 1] It is a plan view showing the configuration of the electric wire with a terminal. [Figure 2] It is a side view showing the configuration of the electric wire with a terminal. [Figure 3] It is a cross-sectional view taken along the III-III section in FIG. 1. [Figure 4] It is a cross-sectional view showing the wire connection part of the terminal and the end of the wire inserted therein. [Figure 5] It is a graph showing the correlation between the value of X and the resistance change rate Z in the electric wire with a terminal.

Embodiments for Carrying Out the Invention

[0008] Exemplary embodiments of the present disclosure will be described with reference to the drawings. 1. Configuration of the electric wire 1 with a terminal It should be noted that there are some ellipsis in the original text (marked as "……" in the translation), as the original text seems to be incomplete in that part. If you can provide the complete original text, a more accurate translation can be made.The configuration of the terminal-equipped wire 1 will be explained based on Figures 1 to 3. As shown in Figures 1 and 2, the terminal-equipped wire 1 comprises a wire 3 and a terminal 5. In Figures 1 and 2, terminals 5 are attached to both ends of the wire 3, but terminals 5 may be attached to only one end of the wire 3.

[0009] As shown in Figure 3, the electric wire 3 comprises a composite conductor 7 and an insulating layer 9. The composite conductor 7 comprises, for example, a central conductor 11, a first conductor layer 13, a second conductor layer 15, and a third conductor layer 17, as shown in Figure 3. In a cross-section perpendicular to the longitudinal direction of the electric wire 3, the shape of the composite conductor 7 is, for example, circular. The diameter of the composite conductor 7 is preferably 7 mm or more and 25 mm or less.

[0010] In a cross-section perpendicular to the longitudinal direction of the electric wire 3, the central conductor 11 is located at the center of the composite conductor 7. The central conductor 11 is a linear member that extends along the longitudinal direction of the electric wire 3. The central conductor 11 may be a single wire or may be made by twisting together multiple wires. The direction in which the multiple wires are twisted together may be clockwise or counterclockwise.

[0011] In a cross-section perpendicular to the longitudinal direction of the electric wire 3, the shape of the central conductor 11 is, for example, circular. The diameter of the central conductor 11 is preferably 1 mm or more and 5 mm or less. The central conductor 11 is preferably made of copper wire, copper alloy wire, iron wire, steel wire, nickel-steel wire, or titanium wire. When the central conductor 11 is made of one of these materials, the value of X, described later, becomes even smaller within the range of positive values.

[0012] The first conductor layer 13, the second conductor layer 15, and the third conductor layer 17 are provided on the outer periphery of the central conductor 11. The first conductor layer 13, the second conductor layer 15, and the third conductor layer 17 correspond to two or more conductor layers. The outer periphery refers to the outer periphery of the central conductor 11 in a cross-section perpendicular to the longitudinal direction of the electric wire 3.

[0013] The second conductor layer 15 is located on the outer circumference of the first conductor layer 13. The third conductor layer 17 is located on the outer circumference of the second conductor layer 15. In the configuration shown in Figure 3, the first conductor layer 13 is the innermost layer among the two or more conductor layers. Also, in the configuration shown in Figure 3, the third conductor layer 17 is the outermost layer among the two or more conductor layers.

[0014] The first conductor layer 13, the second conductor layer 15, and the third conductor layer 17 are each composed of multiple conductors 21 arranged in the circumferential direction. The circumferential direction is the direction around the center of the electric wire 3 in a cross section perpendicular to the longitudinal direction of the electric wire 3. The number of conductors 21 (hereinafter referred to as conductor 21A) in the first conductor layer 13 is, for example, 6. The number of conductors 21 (hereinafter referred to as conductor 21B) in the second conductor layer 15 is, for example, 12. The number of conductors 21 (hereinafter referred to as conductor 21C) in the third conductor layer 17 is, for example, 18.

[0015] Each of the multiple conductors 21 is a linear member extending along the longitudinal direction of the electric wire 3. The conductors 21 may be single wires or multiple wires twisted together. The direction in which the multiple wires are twisted together may be clockwise or counterclockwise. The direction in which the multiple wires are twisted together may be the same or different among the multiple conductors 21.

[0016] In a cross-section perpendicular to the longitudinal direction of the conductor 21, the shape of the conductor 21 is, for example, circular. The diameter of the conductor 21 is preferably 1 mm or more and 5 mm or less. The diameters of multiple conductors 21 contained in the same layer are, for example, the same. For example, the diameters of multiple conductors 21A contained in the first conductor layer 13 are, for example, the same. Also, the diameters of multiple conductors 21B contained in the second conductor layer 15 are, for example, the same. Also, the diameters of multiple conductors 21C contained in the third conductor layer 17 are, for example, the same. Furthermore, the diameters of the central conductor 11 and conductors 21A to 21C are, for example, the same.

[0017] The conductor 21A included in the first conductor layer 13 and the conductor 21B included in the second conductor layer 15 contain aluminum. The conductor 21A included in the first conductor layer 13 and the conductor 21B included in the second conductor layer 15 are made of, for example, aluminum. The conductor 21A included in the first conductor layer 13 and the conductor 21B included in the second conductor layer 15 have a plating layer on the surface of the main body made of, for example, aluminum. The plating layer has a function to suppress electrolytic corrosion, for example. The plating layer is, for example, a tin plating layer. The first conductor layer 13 and the second conductor layer 15 correspond to aluminum layers.

[0018] The conductor 21C included in the third conductor layer 17 contains copper. The conductor 21C included in the third conductor layer 17 is made of, for example, copper. The conductor 21C included in the third conductor layer 17 has a plating layer on the surface of the main body made of, for example, copper. The plating layer has a function to suppress galvanic corrosion, for example. The plating layer is, for example, a tin plating layer. The third conductor layer 17 corresponds to the copper layer.

[0019] For example, the multiple conductors 21 included in the first conductor layer 13, the second conductor layer 15, and the third conductor layer 17, as well as the central conductor 11, are twisted together. The direction in which the multiple conductors 21 and the central conductor 11 are twisted together as a main strand, and the direction in which the conductors 21 or the central conductor 11 are twisted together as sub-strands, may be the same or may be different.

[0020] In wire 3, the value of X is defined by the following equation (1). Equation (1) X=(d0×K0+2×Σ(d i ×K i )-D×K T ) / D In equation (1), D is the diameter before crimping of the portion consisting of the central conductor 11 and two or more conductor layers. In the configuration shown in Figure 3, the portion consisting of the central conductor 11 and two or more conductor layers is the composite conductor 7.

[0021] In equation (1), K T is the coefficient of linear expansion of the material of terminal 5. When terminal 5 is made of copper, K Tis the coefficient of linear thermal expansion of copper. The unit of the coefficient of linear thermal expansion is 1 / °C. d0 is the diameter of the central conductor 11. K0 is the coefficient of linear thermal expansion of the central conductor 11. d i d is the diameter of the conductor 21 contained in two or more conductive layers. In the configuration shown in Figure 3, d i D, d0, and d in equation (1) are the diameters of the conductors 21 included in the first conductor layer 13, the second conductor layer 15, or the third conductor layer 17. i These values ​​are for use at room temperature and before crimping. Note that the material of terminal 5 may be something other than copper, for example, a copper alloy. For example, if the material of terminal 5 is a copper alloy, K T The value of is the coefficient of linear thermal expansion of the copper alloy.

[0022] K i The diameter is d i This is the coefficient of linear expansion of conductor 21. Σ(d i ×K i ) was calculated for each of the two or more conductive layers (d i ×K i This is the sum of ) i ×K i ) was calculated for each of the first conductor layer 13, the second conductor layer 15, and the third conductor layer 17 (d i ×K i This is the sum of ( ).

[0023] In the configuration shown in Figure 3, Σ(d i ×K i Specifically, the coefficients are as follows: Let d1 be the diameter of conductor 21A contained in the first conductor layer 13, and let K1 be the coefficient of linear expansion of conductor 21A. Let d2 be the diameter of conductor 21B contained in the second conductor layer 15, and let K2 be the coefficient of linear expansion of conductor 21B. Let d3 be the diameter of conductor 21C contained in the third conductor layer 17, and let K3 be the coefficient of linear expansion of conductor 21C. Σ(d i ×K i ) is the sum of (d1×K1), (d2×K2), and (d3×K3). In the configuration shown in Figure 3, D is specifically the sum of (d0), (d1×2), (d2×2), and (d3×2).

[0024] The value of X is 3.4 × 10⁻⁶ for temperatures above 0°C. -6 It is below / ℃. The value of X is 2.0 × 10 -6 / ℃ or higher 3.4×10 -6 It is preferable that the temperature is below / ℃. The materials of the central conductor 11 and the conductor 21 are changed to K0, K i By changing the value of , the value of X can be adjusted to a desired range. Since the coefficient of linear expansion of each material is known, the material of terminal 5, the material of central conductor 11, the material of conductor 21, D, d0, d i Once this is determined, the value of X is uniquely determined and can be calculated.

[0025] As shown in Figure 3, the insulating layer 9 covers the composite conductor 7. The insulating layer 9 also covers the third conductor layer 17, which corresponds to a conductor layer. However, as shown in Figures 1 and 2, at the end 3A in the longitudinal direction of the electric wire 3, the composite conductor 7 is not covered by the insulating layer 9 and is exposed. End 3A consists only of the composite conductor 7. Examples of materials for the insulating layer 9 include resin and rubber.

[0026] As shown in Figures 1 and 2, terminal 5 is electrically connected to the electric wire 3 at end 3A. Terminal 5 contains copper. Terminal 5 is made of, for example, copper. Terminal 5 has a plating layer on the surface of its main body, which is made of, for example, copper. The plating layer has a function to suppress galvanic corrosion, for example. The plating layer is a tin plating layer, for example.

[0027] Terminal 5 comprises a wire connection portion 31 and a mating connection portion 33. Terminal 5 is, for example, a ring crimp terminal. When terminal 5 is a ring crimp terminal, the wire connection portion 31 is a hollow cylindrical part. The mating connection portion 33 is, for example, a flat plate-shaped part. In accordance with JIS C2805:2010 (Crimping terminals for copper wires), terminal 5 can be selected that has an inner diameter of the wire connection portion 31 suitable for the cross-sectional area of ​​the composite conductor 7 of the wire 3.

[0028] End portion 3A is inserted into the wire connection portion 31. With end portion 3A inserted into the wire connection portion 31, the wire connection portion 31 is crimped. As a result, terminal 5 is fixed to wire 3. A commercially available crimping jig or compression jig can be used for crimping.

[0029] The terms in equation (1) have the following meanings. Figure 4 is a cross-sectional view showing the wire connection part 31 and the composite conductor 7 inserted inside it. The inner diameter of the wire connection part 31 and the diameter of the composite conductor 7 are both D.

[0030] When the terminal-equipped wire 1 becomes hot, the inner diameter of the wire connection part 31 expands, and the diameter of the composite conductor 7 also expands. The expansion of the inner diameter of the wire connection part 31 means that the hollow portion of the wire connection part 31 expands. The expansion of the diameter of the composite conductor 7 means that the diameter of the composite conductor 7 increases. In equation (1), "D × K" T " represents the magnitude of the expansion of the inner diameter of the wire connection part 31 when the terminal wire 1 becomes hot. In equation (1), "d0 × K0 + 2 × Σ(d i ×K i ) represents the magnitude of the diameter expansion of the composite conductor 7 when the terminal-attached wire 1 becomes hot. The "t / 2" shown in Figure 4 is the value obtained by multiplying t by 1 / 2. t is "d0 × K0 + 2 × Σ(d i ×K i )" to "D×K T This is the value obtained by subtracting the following. In other words, t means the value obtained by subtracting the magnitude of the inner diameter expansion of the wire connection part 31 from the magnitude of the diameter expansion of the composite conductor 7. If the value of X is 0 / ℃ or higher, then 3.4 × 10 -6 A temperature of / ℃ or lower means that the expansion of the diameter of the composite conductor 7 is greater than the expansion of the inner diameter of the wire connection portion 31, and the difference between the two is relatively small.

[0031] 2. Effects of terminal-equipped wires 1 and 3 (1A) The value of X in wire 3 is 3.4 × 10⁻⁶ for temperatures of 0 / ℃ or higher. -6The resistance is below / °C. Therefore, the resistance ratio of the terminal-equipped wire 1 does not easily increase even in environments with drastic temperature changes. Environments with drastic temperature changes include, for example, operating environments between -40°C and 125°C. This effect is further supported by the test results in the examples described later.

[0032] (1B) The conductors 21 contained in the first conductor layer 13 and the second conductor layer 15 contain aluminum. Therefore, the electric wire 3 is lightweight. (1C) The conductor 21 contained in the third conductor layer 17 contains copper. Therefore, the electrical conductivity of the electric wire 3 is high.

[0033] (1D) The central conductor 11 is, for example, a copper wire, an iron wire, a steel wire, a nickel-steel wire, or a titanium wire. In this case, the value of X can be made even smaller within the range of positive values. 3. Examples (3-1) Manufacturing of terminal-equipped electric wires 1A to 1C We manufactured terminal-equipped wires 1A to 1C. Terminal-equipped wires 1A to 1C share the following common features and differ in the following features.

[0034] (i) Common points The terminal-equipped wires 1A to 1C had the configurations shown in Figures 1 to 3. The cross-sectional shape of the composite conductor 7 was circular. The diameter D of the composite conductor 7 was 14.7 mm before crimping. The cross-sectional shape of the central conductor 11 was circular. The diameter d0 of the central conductor 11 was 2.1 mm.

[0035] The first conductor layer 13 contained 6 conductors 21. The second conductor layer 15 contained 12 conductors 21. The third conductor layer 17 contained 18 conductors 21.

[0036] The multiple conductors 21 contained in the first conductor layer 13 and the second conductor layer 15 were each made by twisting together 16 Al-Fe-Zr wires with a diameter of 0.45 mm. The cross-sectional shape of the multiple conductors 21 contained in the first conductor layer 13 and the second conductor layer 15 was circular. The diameter d1 of the multiple conductors 21A contained in the first conductor layer 13 and the diameter d2 of the multiple conductors 21B contained in the second conductor layer 15 were both 2.1 mm.

[0037] Each of the multiple conductors 21 contained in the third conductor layer 17 was made by twisting together 16 tin-plated copper wires, each with a diameter of 0.45 mm. The cross-sectional shape of each of the multiple conductors 21 contained in the third conductor layer 17 was circular. The diameter d3 of each of the multiple conductors 21C contained in the third conductor layer 17 was 2.1 mm. The diameter D of the composite conductor 7, which is 14.7 mm, is the sum of (d0), (d1×2), (d2×2), and (d3×2).

[0038] The central conductor 11, the multiple conductors 21 included in the first conductor layer 13, the multiple conductors 21 included in the second conductor layer 15, and the multiple conductors 21 included in the third conductor layer 17 were twisted together. The terminal 5 was a round crimp terminal made of copper. The wire connection part 31 had a hollow cylindrical shape. The inner diameter of the wire connection part 31 was larger than the diameter D of the composite conductor 7, and was 16.4 mm. A composite conductor 7 was inserted into the wire connection portion 31. Next, the inserted portion was crimped using a crimping jig to form the end portion 3A, thus creating a wire with a terminal 1.

[0039] (ii) Differences In terminal-equipped wire 1A, the central conductor 11 was made of 16 strands of aluminum wire with a diameter of 0.45 mm twisted together. In terminal-equipped wire 1B, the central conductor 11 was made of 16 strands of tin-plated copper wire with a diameter of 0.45 mm twisted together. In terminal-equipped wire 1C, the central conductor 11 was made of 32 strands of iron wire with a diameter of 0.32 mm twisted together.

[0040] Table 1 shows the values ​​of t and X for terminal-equipped wires 1A to 1C. t is the numerator of equation (1), where (d0 × K0 + 2 × Σ(d i ×K i )-D×K T )」. t / D is equal to X. Table 1 also shows the values ​​of t and X when the central conductor 11 is titanium wire in terminal-equipped wires 1A to 1C. K T The value of was taken as the coefficient of linear thermal expansion of copper.

[0041] [Table 1]

[0042] (3-2) Evaluation of terminal-equipped wires 1A~1C Each of the terminal-equipped wires 1A to 1C was evaluated using the following procedure. First, Rt and Rc were measured. Rt is the electrical resistance between point P1 on wire 3 and point P2 on the mating connector 33, as shown in Figure 1. The electrical connection path between point P1 and point P2 includes the connection between wire 3 and terminal 5. Rc is the electrical resistance between point P1 and point P3 on wire 3.

[0043] Next, the resistance ratio Y was calculated by substituting Rt and Rc into the following equation (2). Equation (2) Y = (Rt / Rc) × 100 Next, terminal-equipped wires 1A to 1C were placed in an environment where a heat cycle was repeatedly performed. The heat cycle consisted of raising the temperature to 125°C, holding it at 125°C for 1 hour, cooling it to -40°C, and holding it at -40°C for 1 hour, and repeating this cycle 100 times.

[0044] After the heat cycle was completed, the resistance ratio Y was calculated again. The resistance ratio Y calculated before the heat cycle was denoted as Y1. The resistance ratio Y calculated after the heat cycle was denoted as Y2. The change in resistance ratio Z (%), expressed by the following equation (3), was calculated.

[0045] Equation (3) Z = Y² - Y¹ Figure 5 shows the values ​​of X and the resistance ratio change Z for terminal-equipped wires 1A to 1C. As shown in Figure 5, the smaller the value of X within the positive range, the smaller the resistance ratio change Z. A small resistance ratio change Z indicates that the resistance ratio of terminal-equipped wire 1 does not increase easily even in environments with drastic temperature changes. (X value 0 / °C or higher, 3.4 × 10⁻⁶) -6 When the temperature was below / ℃, the change in resistance ratio Z was particularly small.

[0046] 4. Other Embodiments Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be implemented in various modified forms.

[0047] (1) In the above embodiment, the electric wire 3 had three conductor layers consisting of a first conductor layer 13, a second conductor layer 15, and a third conductor layer 17. The number of conductor layers may be 2, 4, 5, 6, etc. If the number of conductor layers is 2, the number of aluminum layers can be 1 and the number of copper layers can be 1. If the number of conductor layers is N, for example, the number of aluminum layers can be 1 to (N-1) and the remaining layers can be copper layers. N is a natural number of 3 or more.

[0048] If the number of conductive layers is 2, then Σ(d i ×K i ) is the sum of (d1 × K1) and (d2 × K2). If the number of conductive layers is 4, then Σ(d i ×K i ) is the sum of (d1×K1), (d2×K2), (d3×K3), and (d4×K4). d4 is the diameter of the conductor 21 included in the fourth conductor layer located on the outer periphery of the third conductor layer 17. K4 is the coefficient of linear expansion of the conductor 21 with diameter d4.

[0049] (2) The electric wire 3 may further include a shield layer, a sheath, etc. (3) The composite conductor 7 may further include other layers between the central conductor 11 and the first conductor layer 13. The composite conductor 7 may further include other layers between the third conductor layer 17 and the insulating layer 9.

[0050] (4) The function of one component in each of the above embodiments may be divided among multiple components, or the function of multiple components may be performed by one component. Also, some of the configurations of each of the above embodiments may be omitted. Also, at least some of the configurations of each of the above embodiments may be added to, replaced with, etc., the configurations of other embodiments.

[0051] (5) In addition to the terminal-equipped wire 1 described above, this disclosure can also be realized in various forms, such as a system that uses the terminal-equipped wire 1 as a component, a method for manufacturing the terminal-equipped wire 1, etc. [Explanation of Symbols]

[0052] 1, 1A, 1B, 1C... Wire with terminal, 3... Wire, 3A... End, 5... Terminal, 7... Composite conductor, 9... Insulation layer, 11... Center conductor, 13... First conductor layer, 15... Second conductor layer, 17... Third conductor layer, 21... Conductor, 31... Wire connection part, 33... Mating connection part

Claims

1. The central conductor and Two or more conductor layers are provided on the outer circumference of the central conductor, each consisting of multiple conductors arranged in the circumferential direction, An insulating layer covering the aforementioned conductor layer, A terminal crimped to the end of the conductor, Equipped with, The two or more conductive layers mentioned above are An aluminum layer composed of aluminum-containing conductors arranged in the circumferential direction, A copper-containing conductor is arranged in the circumferential direction, and the copper layer is positioned on the outer periphery of the aluminum layer, Includes, The value of X defined by the following formula (1) is 0 / °C or greater, 3.4 × 10 －６ It is below / ℃. Electrical wire with terminals. Equation (1) X = (d ０ ×K ０ +2×Σ(d) ｉ ×K ｉ ) - D×K Ｔ ) / D (In formula (1), D is the diameter before caulking of the portion composed of the central conductor and the two or more conductor layers. K Ｔ is the linear expansion coefficient of the material of the terminal. d ０ is the diameter of the central conductor before caulking. K ０ is the linear expansion coefficient of the central conductor.d ｉ is the diameter before caulking of the conductor included in the two or more conductor layers. K ｉ is the linear expansion coefficient of the conductor having a diameter of d ｉ . Σ(d ｉ ×K ｉ ) is the total value of (d ｉ ×K ｉ ) calculated for each of the two or more conductor layers.)

2. A wire with terminals as described in claim 1, The central conductor is made of copper wire, iron wire, steel wire, nickel-steel wire, or titanium wire. Electrical wire with terminals.

3. A wire with terminals as described in claim 1, The material of the terminal is copper or a copper alloy. Electrical wire with terminals.

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